中文摘要：

当前基于体系结构的软件可靠性评估技术存在2个问题：不适合具有并行性质的软件和难以分析部件级的失效恢复行为。针对这2个问题，以管道一过滤器风格的并行软件为研究对象，该文使用基于时间的Petri网分析了管道一过滤器风格的并行软件运行阶段可靠性，并根据Petri网模型的特点，提出了一种分解模型和近似求解方法。数字实例证明了该方法的有效性和简便性。

英文摘要：

Current architecture-based software reliability evaluation is suitable for sequential software but not parallel software, and it is difficult to analyze the failure and restart behavior of component. To solve these problems, parallel software with pipe-filter style is selected as the research object and a new model is proposed to analyze the reliability of it by using time-based Petri nets. According to the characteristics of its model, a specifical solution to decompose and compute approximately the Petri net model is presented and it can avoid the explosion of state space. Numerical examples show the method is valid and convenient.